The first two steps in obtaining certification in Scuba Diving are ensuring that you are a fairly proficient swimmer and you get medical permission from your doctor to take sports. If you are in good and comfortable public health in water, then you must be able to dive without problems.
These centers or shops must be listed on the yellow page and you can also check with sites from several large scuba diving certification agencies such as rice or Naui because they will also have a list. Sometimes scuba diving courses are offered at universities too. You can consider scuba diving class in Phuket to learn scuba with your friends.
Make sure that your course is interested in taking and certified instructors with one of the big scuba diving training institutions. This will ensure that you get safe training right for skills both technical and practical background knowledge needed for certification as a scuba diver. You also want to end up with an internationally recognized certification card if you want to go scuba diving in various locations around the world.
The duration of classwork sessions and swimming pools varies from a very intensive weekend (with a reading face) to once a week for several weeks. Open waters will usually take two more days. Dive center located in the tropics also offers basic certification programs that are the last few days for a week. Scuba diving does not involve new skills and to learn them all for a full week may be too much for some people.
As for the Scuba Diving Certification Training Institute is the best, no organization is better recognized than others. Padi is the most popular in the world but not necessarily better than Naui or SSI. The Maui course is often more technical in class than offered by rice but both will be enough to train you to become a scuba diver.